What are stem cells, and what do they do?

 

Cells in the body have specific purposes, but stem cells are cells that do not yet have a specific role and can become almost any cell that is required.

Stem cells are undifferentiated cells that can turn into specific cells, as the body needs them.

Scientists and doctors are interested in stem cells as they help to explain how some functions of the body work, and how they sometimes go wrong.

Stem cells also show promise for treating some diseases that currently have no cure.

Sources of stem cells:

Stem cells originate from two main sources: adult body tissues and embryos.

Types of stem cells:

Totipotent: These stem cells can differentiate into all possible cell types. The first few cells that appear as the zygote starts to divide are totipotent.

Pluripotent: These cells can turn into almost any cell. Cells from the early embryo are pluripotent.

Multipotent: These cells can differentiate into a closely related family of cells. Adult hematopoietic stem cells, for example, can become red and white blood cells or platelets.

Unipotent: These can only produce cells of one kind, which is their own type. However, they are still stem cells because they can renew themselves. Examples include adult muscle stemcells.

Embryonic stem cells are considered pluripotent instead of totipotent because they cannot become part of the extra-embryonic membranes or the placenta.